(a) Technical Field
The present disclosure relates to a fuel tank of a vehicle using LPG (Liquefied Petroleum Gas) as a fuel. More particularly, it relates to a LPG bomb apparatus capable of maintaining a constant pressure therein.
(b) Description of the Related Art
In existing LPG vehicles using LPG as a fuel, the LPG is evaporated and then supplied to the engines of the vehicles. However, a LPI (Liquefied Petroleum Injection) arrangement in which LPG is directly injected as a high-pressure liquid-phase by an injector has been mainly used in order to solve a problem such as a poor start-up during cold weather, for example, in winter time.
In a conventional arrangement, a fuel pump may lose its suction capability due to cavitations generated when temperature, pressure or composition of fuel within the LPG bomb are varied abruptly in the course of recharging LPG.
In a related art, Korean Application No. 10-2010-0097570, in order to solve the above-mentioned problem, discloses that a fuel is charged through a liquid-phase outlet formed on the front end of a charging pipe and a gas-phase outlet formed on an upper part of the charging pipe concurrently to maintain constantly a gas-phase side pressure in the LPG bomb and to prevent a charge delaying phenomenon caused by a pressure increase in the gas phase side.
FIG. 1 is a view showing a LPG bomb apparatus according to the related art in which a part of fuel injected through a fuel charging unit 30 is evaporated and is charged to a gas-phase side V, and another part of fuel is charged to a liquid-phase side L via a liquid-phase charging pipe 51. The fuel in the liquid-phase side L is sucked by a fuel pump 20.
FIG. 2 is a view showing a LPG bomb apparatus according to a related art in which a first check valve 70 and a second check valve 90 are formed on a charging conduit 33 of a LPG bomb 10 and suck fuel to a fuel pump. The first check valve 70 is formed on the front side of a suction conduit and the second check valve 90 is formed on a side of a fuel motor 20.
Generally there is no problem in vehicles that are fully charged and then restarted after automatically cutting-off the charging, while a pressure in a LPG bomb is increased again after the pressure in the LPG bomb was decreased. However, in cases in which the vehicles are charged frequently with small quantities of LPG and driven at low speeds repeatedly to increase temperature in the LPG bomb, start-up of the vehicles may be impossible if it is attempted to re-start the vehicles at the moment when the pressure in the LPG bomb is decreased during charging.
Due to this, the pressure before start-up of the vehicle is maintained even though the pressure in the LPG bomb is decreased by a check valve used in an ordinary suction pipe conduit during charging, and after start-up, heat remains in the fuel pump to form high pressure in the suction pipe conduit when compared with the LPG bomb.
Therefore, when trying to restart the vehicles after charging, it is impossible to restart the vehicles because the pressure in the LPG bomb is formed lower than the pressure in the suction pipe conduit and thus the fuel within the LPG bomb is not inflowed smoothly into the suction pipe.
Thus, there is a need for an apparatus which can improve poor start-up performance after charging even when a vehicle is frequently charged with LPG by small quantities of fuel and is restarted after charging, by allowing a fuel temperature in a LPG bomb preferably to be maintained, and thus not decreased.
The disclosure in the background art is only to assist to understand of the background of the present invention, but it is not understood that the disclosure is a prior art known to those skilled in the art.